Extron electronic 4LDXI, 4LQXI Programming the System 4xi Series Switchers, RS-232 Connections

Appendix A • RS-232 Programmer’s Guide

Programming the System 4xi Series Switchers

This section covers the commands for a host to setup and control a System 4xi series switcher through the RS-232 port. The material included covers the System 4LDxi and the System 4LQxi switchers. Commands or parameters that apply to specific models will be pointed out, otherwise, all references will simply say “System xi4 ”.

RS-232 Connections

A standard RS-232 port is					￿￿￿￿￿￿
available on the back of
the System 4xi for use by					￿￿￿￿￿
a host system. The
connections are as
follows:
		Figure A-1. The RS-232, 9-pin D Connector on the Rear Panel
	RS-232 Pin Connections
Pin	Signal	Pin	Signal	Pin	Signal
1	n/c	4	Tx2	7	n/c
2	Tx	5	Gnd	8	Rx2
3	Rx	6	n/c	9	n/c

_______ Rx2 and Tx2 are used to communicate with a slave switcher (do not connect to

or use these pins)

RS-232 Protocol

The default protocol is:

9600 baud, 8-bits, no parity, 1 stop bit and no flow-control.

The baud rate can be changed through a front panel menu. (See Chapter 3.)

Program Instruction Levels

The System 4xi recognizes any character that comes in on the RS-232 port as a possible command. Commands can be from either of two groups, or instruction sets. They are as follows:

1.The Simple Instruction Set can be any ASCII character that is recognized by the System 4xi as a command. For this set, there are no codes required to say that a command is coming, or that a command has ended. Simple commands could come from a terminal, or any other controlling device. After the System 4xi gets the command, it will execute it and send an appropriate response to the controlling device.

2.The Advanced Instruction Set consists of more complex instruction strings. Advanced instructions are used when a complete command cannot be defined within one character. Each instruction string must begin with an Escape code (ESC) and end with an End Of Transmission code (EOT). Advanced commands could come from any controlling device capable of composing a command and sending it as a string. The System 4xi will execute any legal command string and send a response string back to the host.

Because of this “open recognition”, commands from the two instruction sets can be intermixed. Both instruction sets are listed and defined on pages that follow.

_______ RS-232 control can also be established from a computer using the Windows®

operating system and Extron’s software. This is covered separately in Chapter 5.

A-1 Extron • System 4xi Switcher Series • User’s Manual